If the United States attacks Iraq, U.S. forces will do much of their fighting in darkness, when their goggles transform night into day, and when the enemy is almost blind.

Night-vision goggles will allow helicopter pilots to swoop closer to buildings and help fighter pilots target Saddam Hussein's tanks. The U.S. Army's advanced gear will enable soldiers to see Iraqi snipers in the shadows.

"There's nobody on the ground who can see clearer or see farther than I can," said Pfc. Joe Adams, 26, of Morrice, Mich., who mans a Humvee-mounted missile for the 2nd Battalion, 327th Infantry of the 101st Airborne Division.

The United States has a significant advantage at night, according to defense analysts and military equipment specialists.

Night-vision goggles are standard equipment for U.S. troops, but many Iraqi soldiers don't have them. U.S. forces have the latest and most advanced gear, while the Iraqis have older, less reliable Russian models.

"They can't see us, but we can see them," said Spc. Steven Griffin, 19, of Louisville, Ky., a Humvee driver for the 2nd Battalion, 387th Infantry of the 101st Airborne. "That's our premium advantage."

U.S. soldiers use two types of night-vision equipment: the infrared goggles and newer devices that show thermal images.

The battery-powered goggles resemble binoculars and attach to a helmet. They amplify existing

light. The amplified scene glows in shades of green on a tiny screen in the eyepiece.

The goggles have a few drawbacks. Soldiers cannot see through smoke, they have a narrow field of view and the devices weigh down their helmets. The goggles are so sensitive that a sudden burst of light can be disorienting.

But soldiers say those are minor inconveniences.

"You can tell what the person is, you can see what they're carrying, you know what kind of gear they've got on," said Pfc. Jacob Moss, 21, of Colorado Springs, a member of Company A, 2nd Battalion, 327th Infantry.

The Army has used the goggles for more than 20 years. They are now standard equipment for U.S. troops and come in a new monocular version that allows soldiers to use their other eye normally, reducing the blinding effect from a sudden burst of light.

The monocular "gives you more flexibility on the battlefield," said Fenner Milton, who heads the Army's Night Vision and Electronic Sensor Directorate. "You can look at a map or see the regular battlefield with a naked eye."

The Army pays about $3,000 for a set of goggles or a monocular.

The Iraqis are likely to have Russian-made goggles that do not have the range or clarity of the U.S. model. The Russian goggles are similar to ones available to hunters and private detectives on the Internet for $359-$2,000.

The other type of night vision relies on thermal technology.

It detects warmth from people or vehicles and displays them in bright colors. It is used primarily for targeting, on everything from a rifle to a tank. Thermal imaging has an advantage over the goggles because it can see through smoke.

In the Army, Apache helicopter pilots and the infantrymen who operate antitank missiles are using a thermal system that can see troops, vehicles and equipment a half-mile away. It's heavy and cumbersome, weighing about 150 pounds, but it's perfect for mounted uses, soldiers say.

Adams, who mans an antitank missile attached to a Humvee, said the thermal device allows him to pick out tiny targets, even a sniper hiding in the woods who would be invisible to the naked eye.

The drawbacks for the thermal gear are its price -- $12,000-$15,000 for rifle sight -- and its larger size. But the Army is developing a smaller version that can be clipped to a helmet.

With thermal equipment, "I can find a target at zero visibility," said Maj. Roy Manauis, who works in PEO Soldier, an Army effort to equip troops with better gear.

Night vision can make the difference in a battle.

When elite Army soldiers tried to arrest warlords in Somalia in 1993, they didn't take goggles because they expected the afternoon raid would only take an hour.

But after two Black Hawk helicopters were shot down, the Rangers and Delta Force soldiers found themselves outnumbered by Somali militia. The U.S. troops sought shelter in a battered building but had no goggles.

"When night fell and they got hung up, they were the same as the enemy," said Jean-Louis "Dutch" DeGay, a former Ranger who now works as an equipment specialist at the Army's Natick Soldier Center. "They didn't have the technological capability they should have."

Without night-vision equipment, soldiers tend to walk more slowly and bunch together, which makes them more vulnerable to enemy fire. "You never want to clump soldiers together," said DeGay. "One large indirect round will destroy every one of them."

By contrast, soldiers in Afghanistan last year had the advantage over al-Qaida and Taliban forces because they had the advanced gear.

Said Spc. Jason Ashline, who fought in Operation Anaconda, "Once night came, it became a one-way fight because we had night vision."